Ventilation – Means combined with window – With air pump
Reexamination Certificate
2000-01-05
2001-10-16
Joyce, Harold (Department: 3749)
Ventilation
Means combined with window
With air pump
C454S351000
Reexamination Certificate
active
06302782
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to electric exhaust fans.
2. Description of Prior Art
The invention relates more particular to exhaust fans that have closable doors to close off the exhaust outlet when the fan is not in use. In present day fans, the closable doors each comprise a slatted closure that is opened by a solenoid that is turn ON when the fan is operating. The door is normally closed by a spring that closes the door when power to the fan and the solenoid is turned OFF. This means that power is supplied to the solenoid while fan is running and requires that the solenoid to be of high quality or the solenoid soon becomes unserviceable. Additionally, the slatted door is not aesthetically attractive and thus fans, which are often fitted in window panes, render the normal view through the window inherently unappealing.
SUMMARY OF THE INVENTION
It is an object of the invention to overcome or at least reduce these problems.
According to the invention there is provided an electric exhaust fan having a housing with a front face and a rear face, an air passage extending between the front face and the rear face, a fan and a first electric drive motor for the fan mounted in the passage, an electric switch circuit to turn the fan ON and OFF, and a door to close off the passage adjacent the front face, in which the door comprises two opposing half shells each mounted to rotate about a respective horizontal axis and having abutting sides that meet together and extend in a common plane horizontally across the passage, and a second electric motor mechanically coupled and arranged to rotate the two shells in opposite direction through approximately 90° to fully open the passage whenever the fan is turned ON.
The second motor may be a reversible motor that is arranged to rotate the shells to close off the passage whenever the first motor is turned OFF.
The shells are preferably convexly arcuate in a direction from the housing towards the front face.
The shells may be each formed with gearing along one respective side wall and the second electric motor has a rotor with a gear that engages the gearing of each shell for rotating the shells.
Each shell may be formed with gearing on a respective opposite side wall, and the shells are mounted so that the opposite side wall gearings mesh with one another.
A water collection channel may be provided under a lower one of the shells to collect any water that falls on the lower shell when the door is open, and a bottom drain in the housing that communicates with the channel to drain away the water.
REFERENCES:
patent: 1792514 (1931-02-01), Spear
patent: 2339363 (1944-01-01), Sutcliffe et al.
patent: 6048263 (2000-04-01), Uchida et al.
patent: 60-88892 (1985-05-01), None
patent: 1-181027 (1989-07-01), None
patent: 1-291035 (1989-11-01), None
Brinks Hofer Gilson & Lione
Joyce Harold
LandOfFree
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